Means for processing miniature electronic components such as capacitors or resistors

ABSTRACT

Miniature electronic component parts such as capacitors or resistors are end conductively coated by use of a part handling plate having a multiplicity of passageways therethrough with walls coated by resilient material to grip the parts. A bank of pins in a press (a) are used to move the parts in the passageways, (b) are used to load the parts into the passageways through the use of a loading plate housing part receiving openings filled with parts by the use of vibration equipment, and (c) are used to discharge the parts from the passageways into the recesses of an unloading plate. The parts are moved in the passageways first to expose one end to be coated and then second to expose the other end of the parts to be coated.

The present application is a continuation-in-part of my prior, copendingapplication, Ser. No. 123,201, filed 2/21/80, now U.S. Pat. No.4,315,184 entitled "Means and Method for Processing Miniature ElectronicComponents such as Capacitors or Resistors", Art Unit 314.

BRIEF SUMMARY OF THE INVENTION AND OBJECTIVES

My invention relates to a means for processing miniature capacitors orthe like useful in applyingg a conductive coating to the ends thereof.The claims of this application include a plate supporting a number ofminiature electronic parts classified in Class 118, subclass 53,according to the Office Action of 8/6/80 in Ser. No. 123,201, requiringrestriction and labeling such claims as Group II claims.

A preliminary examination search was made on the invention whichresulted in the citing of the following patents by the searcher: U.S.Pat. Nos. 4,131,982; 4,089,105; 3,963,456; 3,785,035; 3,710,479;3,727,284; 3,896,654; 3,851,223 and 3,896,451. I was not familiar withthe specific devices shown in these patents. I do not believe thepatents show the inventions claimed herein.

In processing such miniature components, the following features aredesirable to be achieved, among others:

(a) To process parts economically in terms of time and cost, i.e., toprocess parts in batches of hundreds in each operation.

(b) To produce as few defective parts as is feasible and to readilydetect defects.

(c) To utilize relatively economical, low maintenance, easily operated,long life equipment.

It is an object of my invention to provide means to process suchcomponents having the above features. Time saving is a primary advantageof my method and equipment.

My invention will be best understood, together with additionalobjectives and advantages thereof, from the following description, readwith reference to the drawings, in which:

THE DRAWINGS

FIG. 1 is an exploded perspective view of a specific embodiment of someof the equipment used in my invention.

FIG. 2 is a fragmentary vertical sectional view, on enlarged scale,showing partly the same equipment as FIG. 1.

FIG. 3 is a partial vertical sectional view.

FIG. 4 is a perspective view. Certain structure is broken away to revealstructure otherwise hidden.

FIG. 5 is a partial vertical sectional view.

FIG. 6 is a view like FIG. 5 but with some parts in different positions.

FIG. 7 is an enlarged, fragmentary plan view.

FIG. 8 is an elevational schematical representation of some processingequipment.

FIG. 9 is an enlarged perspective view of an electronic component with acoating on one end.

FIG. 10 is a view of FIGS. 5 and 6 with some parts in differentpositions.

FIG. 11 is a fragmentary vertical section showing an inverted parthandling plate.

FIG. 12 is a view like FIGS. 5, 6 and 10 but with some parts indifferent positions.

FIG. 13 is a partial sectional view of parts being unloaded from a partunloading plate.

FIG. 14 is like FIG. 9 but showing a coating on both ends of theelectronic components.

FIG. 15 is like FIG. 7 only showing rectangular configurations of partsand passageways.

FIG. 16 is a fragmentary perspective view, partly in section, furthershowing the rectangular configuration of FIG. 15.

FIG. 17 is like FIG. 15 only showing toothed passageway sidewalls.

DETAILED DESCRIPTION

The purpose of the processing and equipment is to conduct certainoperations on parts, especially to apply to the ends of a miniatureelectronic component 16, in sequence, coatings 34, 36. FIG. 9 shows thepart with coating 34 and FIG. 14 shows the addition of coating 36.

Part 16 could be a chip capacitor or a resistor for example. In size, anexample would be around 1/16×1/16" in cross-section and 3/32 to 5/32"long but the part could be larger or smaller than that. The constructionof such a miniature capacitor or resistor will be understood by thoseskilled in the art. A capacitor, for example, has a sizable number ofconductive layers separated by non-conductive layers. Conductive layersare interfingered as to electrical connection of layers to opposite endsof part 16. In any case, such miniature part 16 needs to have conductivecoatings applied to opposite ends and my invention concerns thatoperation.

The drawings show sequence of operations. FIG. 1 includes, from top tobottom, a part handling plate 10, a part loading plate 12, and a partfeeding body 14. FIG. 2 adds schematically the functions of vibration,vacuum and spring mount to the FIG. 1 parts to load parts in plate 12.FIG. 3 shows part loading plate 12 and part handling plate 10 withelectronic components 16 in place in plate 12.

FIG. 4 shows part punching means 18 used (a) to transfer parts 16 frompart loading plate 12 to part handling plate 10, (b) used to transferparts 16 from one side to the other side of part handling plate 10, andused to unload parts 16 from part handling plate 10.

FIG. 5 shows a step in the sequence of operations involving part pushingmeans 18. A bank of pushers 24 is shown in the upper part of the view,and plates 10, 12, a part unloading plate 20, and part pushing base 22are shown in the lower part of the view. FIG. 6 is like FIG. 5 but withthe pushers 24 of part pushing means 18 in the process of pushing parts16 out of part loading plate 12 and into part handling plate 10. Theends of parts 16 are exposed above the upper face of plate 10.

The method of handling parts 16 shown involves resiliently grippingparts in the part receiving passageways 26 in part handling plate 10.FIG. 7 illustrates resilient gripping of parts. Parts 16 usually areright-rectangular (square or rectangular in cross-section) whereaspassageways 26 are round and normally have a diameter less than themaximum cross-sectional dimension of parts 16. The walls of passageways26 are resiliently coated to accommodate and grip parts 16.

FIG. 8 shows equipment for processing a part handling plate 10 havingthe ends of electronic components 16 exposed above its upper face. Theequipment includes conveying means 28, part coating equipment 30, andpart heating equipment 32, used to coat ends of parts 16 and to bakesuch coatings, FIG. 9 shows coating 34 applied to a first end of a part16.

FIG. 10 is like FIG. 6 but with part handling plate 10 inverted, afterapplying coating 34 and returning plate 10 to part pushing press 18.Parts 16 are being moved by pushers 24 into position exposing theirsecond ends beyond the second face of plate 10, so that the second endscan be coated. FIG. 11 shows plate 10 inverted from its FIG. 10 positionwith the second ends of the parts 16 exposed, ready to run through theFIG. 8 coating equipment.

FIG. 12 shows part pushing press 18 in the process of unloading partsfrom plate 10 into part unloading plate 20. FIG. 13 shows parts 16 beingdumped out of plate 20. FIG. 14 shows part 16 with a coating 36 on itssecond end in addition to coating 34 on its first end.

In the class of miniature electronic components needing conductivecoatings to be applied to their ends, probably about 95% of thoseproduced by component manufacturers are 0.050" to 0.200" in length (alittle more than 3/64" to a little more than 3/16"). Although somelonger parts are produced, at present only that range of lengths areprocessed on the equipment disclosed herein. Plates 10 presentlyproduced are about 0.350" (3/8" is 0.375"). It is preferred that thelength of each passageway will be at least 150% of the maximum length ofparts to be handled therein. Reasons to fabricate plates 10 of at leastabout that thickness include (a) to provide sufficient strength,including sufficient strength of the central web 44 and (b) to be ableto accomodate most lengths of parts 16. Parts 16 are continuouslygripped by resilient walls in passageways 26 in plate 10 as they aremoved to a first position exposing one end of parts 16 for coating andto a second position exposing the opposite end of parts 16 for coatingand as they are unloaded. The resilient coating of the walls ofpassageways 26 extends from face to face of plate 10.

The foregoing description describes some of the principal operations andequipment involved in my invention. I will now review them in moredetail.

A basic part of my processing system is part handling plate 10. It has amultiplicity of part receiving passageways 26 having walls uniformly andcontinuously coated from face to face of plate 10 with resilientmaterial. I will now describe my preferred structure of plate 10. It isformed of metal with a recess 40 in each face throughout the majorportions of the face to the marginal areas 42. This leaves a central web44 of metal which has a multiplicity of bores 46. A resilient plasticmaterial 48 is used to fill receses 40 and bores 46 except for leavingpart receiving passageways 26. Material 48 provides resilient walls forpassageways 26, to receive and grip parts in the manner particularlyillustrated in FIG. 7. The material 48 can be selected from variousapplicable plastics or rubbers. An example is a pliable silicone rubber.Those skilled in the art will understand the selection of applicablematerials and methods, tooling, etc., to form plate 10. In the claimswhen material 48 is described as "resilient plastic" that term isdefined to include plastics or natural or artificial rubbers which aresuitable for usage. The purpose of having recesses 40 (rather thanmerely to coat bores 46) is to better hold the plastic material 48 inplace.

Parts 16 usually will be square or rectangular in cross-section. Even ifthe parts 16 were circular in cross-section, the action of the walls ofpassageways 26 in gripping parts 16 would be similar. If the circulardiameter of each passageway 26 should be less than the maximum lateraldimension of part 16 of if passageway 26 is rectangular in cross-sectiona dimension of passageway 26 such as its width should be less than thecorresponding minimum dimension of part 16 such as the width of arectangular part in order to continuously resiliently grip part 16 inall positions in passageway 26 whether part 16 protrudes from an end ofpassageway 26 or whether part 16 is centered or otherwise completelycontained in passageway 26.

The basic method of handling parts 16 in passageways 26 consists of (a)inserting the parts into the passageways, (b) moving the parts so firstends are exposed beyond the face of plate 10, i.e., FIGS. 6 and 8, and(c) moving parts 16 so the second ends are exposed beyond the secondface of plate 10, i.e., FIGS. 10 and 11. The exposed ends of parts 16are coated by the equipment shown in FIG. 8 after steps (b) and (c)above.

I will now deal with the insertion of parts 16 into passageways 26 ofpart handling plate 10. The part loading plate 12 and the part feedingbody 14 and the use of vibration and vacuum to insert parts 16 in theholes 50 of plate 12 follow practices used before in the prior art.Somewhat similar equipment and processes are utilized in some of thepatents identified in the earlier part of this specification.

Part receiving body 14 has a hopper cavity 52 which receives theelectronic components 16 in bulk. An open face 54 of cavity 52 iscovered by part loading plate 12 and part handling plate 10 that areoriented by alignment pins 56 on body 14 which extend through alignmentopenings 58, 60 in plates 12, 10 respectively. Components 16 are loadedin cavity in the manner demonstrated in FIG. 1. Then the assembly isinverted as shown in FIG. 2. As the application of vibration and vacuum62 to a vibrator base 63 and the use of suitable spring mounts 64 forbase 63 are old and familiar expedients in the art to load parts in aplate like part loading plate 12, I will only observe that vacuum isapplied to the lower ends of passageways 26 to help fill holes 50 inplate 12 with parts 16 as the assembly is being vibrated. Followingcommon practices, holes 50 are slightly larger than parts 16 but not solarge that they will fit in any way but with their longitudinal axisvertical, so that they will be presented in end-forward directions topassageways 26. The upper ends 66 of holes 50 are flared to more readilyreceive parts 16. Holes 50 could be circular or rectangular incross-section as the only orientation required of parts 16 is that theybe presented in an end-forward direction. The action of filling holeswill be slightly faster if holes 50 are circular in cross-section. Togive an example, in one sized load plate 12, 2145 holes 50 were 100%filled with parts 16 in 8-10 seconds. In a larger size, there were 4233holes 50.

Part pushing means 18 is a form of press and includes a base 22 havingupstanding alignment pins 70 that fit into alignment openings 72 in partunloading plate 20, into alignment openings 60 in part handling plate 10and into alignment openings 58 in part loading plate 12 to hold theplates in proper alignment.

The upper parts of press 18 include an upper plate 74. a rack 76upstanding from plate 74, a pinion 78 engaged with rack 76, and apivotally mounted handle 80 secured to a common shaft 82 with pinion 78and rotating pinion 78 when handle 80 is manually pivoted upper plate 74up and down. The bearing for shaft 82 is supported by an arm 84upstanding from base 22. Other standards can be substituted for arm 84and cams or an air cylinder can be substituted for rack and pinion 76,78 to close press 18.

Suitably mounted on upper press plate 74 in depending position is a bankof pin pushers 24 mating with openings 50 in part loading plate 12,mating with passageways 26 in part handling plate 10, and mating with amultiplicity of recesses 86 in part unloading plate 20. As handle 80 isoperated, parts 16 are forced from positions in holes 50 of plate 12into passageways 26 in plate 10. The first position of parts 16 inpassageways 26 is shown in the sequence of FIGS. 5-6 to leave the upperends of parts 16 in a plane above the upper face of plate 10 so thatthey can be coated. Stop 90 pivotally mounted on stripper plate 92 canbe positioned upright to stop upper plate 74 when pins 24 have sooriented the ends of parts 16 in the FIG. 6 position.

The second position of parts 16 in passageways 26 is shown in FIG. 10with the second ends of parts 16 disposed in a plane below the lowerface of plate 10 in position to be coated. A second stop 94 pivotallymounted on stripper plate 92 can be positioned in upright position tostop upper press plate 74 when the FIG. 10 position of the ends of parts16 is reached. Two FIG. 10 type operations can be substituted for a FIG.6 and a FIG. 10 type operation, i.e., if a FIG. 10 operation isconducted and then the plate 10 is inverted and the operation repeated,both ends of parts will have been disposed in position to be coated.

An assortment of shims can be substituted for the pivoted stops 90, 94.Such shims would be interposed between stripper plate 92 and upper pressplate 74.

Stripper plate 92 is supported on upper press plate 74 by rods 100slidably mounted in openings 102 in plate 74 and secured to stripperplate 92. The enlarged ends 104 of rods 100 act as abutments limitingdownward movement of stripper plate 92 relative to upper press plate 74to a position preferably covering the lower ends of pins 24, as in FIG.5. Plate 92 has openings 106 mating with pins 24. Compression springs108 on rods 100 between upper press plate 74 and stripper plate 92normally urge stripper plate 92 to the FIG. 5 lower position coveringpins 24. The purposes of stripper plate 92 include (a) to normally coverand protect pin pushers 24 during insertion and removal of plates 10,12, 20, and (b) to strip part handling plate 10 from the bank of pins 24when the press 18 is opening, as otherwise the resilient walls ofpassageways 26 may grip pins 24 and plate 10 may therefore tend to raisewith upper press plate 74.

Part handling plate 10 is removed from press 18 after the FIGS. 5-6sequence to apply coating 34 to the first end of electronic components16, and after the FIG. 10 operation to apply coating 36 to the secondends of components 16 exposed as illustrated in FIG. 11. The equipmentshown in FIG. 8 demonstrates state-of-the-art coating equipment 30 andovens 32, so I have shown the equipment schematically.

Plate 10 is shown schematically to be mounted on a traveling platform109 having upstanding pins 110 fitting in alignment holes 60 in plate 10to secure it in position. The conveying means 112 (implicitly a screwmechanism) actually would not be common to both coating station 30 andoven 32, i.e., the ends of parts 16 first would be coated and then theplate 10 would be placed on a conveyor of an oven.

As indicated, the coating mechanism 30 is of a common type having ametal roller 120, usually having a doctor blade (not shown) controllingthe amount of coating passing onto roller 120 and then onto the ends ofparts 16, and having a reservoir function 122 in supplying the coatingmaterial to the roller/doctor blade mechanism.

I will not further describe the coating and baking functions in applyingconductive metalized coatings 34,36 to the ends of capacitors orresistors 16. The type of coating will follow state-of-the-art materialssuch as a fine milled silver compound in a resin base cured by heatingin an oven.

My process of orienting the parts for processing by the equipmentrepresented in FIG. 8 represents high efficiency in time consumed. Usingthe equipment shown in FIGS. 1 and 2, the example of time given beforeis inserting about 2000 or about 4000 parts 16 in openings 50 in partloading plate 12 in about eight to ten seconds. In the process of theFIGS. 5-6 operation getting ready to coat the parts with the FIG. 8equipment, an example is about ten seconds. To orient parts 16 in press18 the second time (FIG. 10), again would involve around ten seconds.Silvering the first or second ends of parts 16 can be accomplished inabout ten seconds. Curing the coating in an oven may vary between abouttwo and a half minutes and five minutes, depending on the type of silveror other compound used to coat the ends of part 16. After coating andfiring, inspection can be accomplished merely by glancing at plate 10,as any uncoated ends of parts 16 would be quite evident. However, it israre to have an uncoated part 16.

Unloading parts 16 from passageways 26 of plate 10 into recesses 86 inunloading plate 20, as demonstrated in FIG. 12, is another ten secondtype operation. FIG. 13 indicates unloading of plate 20.

The claims of this application include a plate 10 supporting a number ofminiature electronic parts 16 in a multiplicity of passageways 26extending from face to face of body 10. Each passageway 26 has resilientwalls and each has a dimension smaller than the corresponding dimensionof each part 16 so that when the parts 16 are forced into passageways 26they are resiliently gripped.

Passageways 26 are shown in FIG. 7 to be circular in cross-section butmay have other cross-sections as long as each passageway 26 has adimension smaller than a corresponding dimension of an associated part16 so that the part 16 is resiliently gripped, as indicated in FIGS. 15,16 and 17. FIG. 15 is like FIG. 7 but, along with FIG. 16, indicatesbores 46 of rectangular cross-sections, passageways 26 of rectangularcross-sections and parts 16 of rectangular cross-sections, in which theminor cross-section "Y" of the passageway is somewhat less than theminimum cross-section "X" of the parts 16 (according to the tolerancesof parts 16) so that each part 16 is gripped at least across its minoraxis by the associated passageway 26. My prior, copending patentapplication Ser. No. 195,347, filed 10/9/80, in Art Unit 162, entitled"Means and Method for Processing Miniature Electronic Components", showspassageways and parts of rectangular cross-sections.

FIG. 17 shows modified rectangular passageway cross-sections which arelike those in FIGS. 15 and 16 except the minimum distances across theminor axes of the passageways 26 are defined by the distances betweenbosses or teeth 140 protruding beyond the normal sidewalls 142 ofpassageways 26. The parts 16 are gripped by one or more pairs of teeth140 extending from the sides of passageways 26. In the configurationshown, two pairs of bosses are shown. In another configuration used, onepair was used, etc. The idea of the toothed or notched construction isto minimize the amount of resilient material in the walls of passageways26 that must be displaced to force the parts into the grippingpassageways. This can be a particularly desirable construction when thedifference in cross-sectional widths of a part is relatively greataccording to the minimum and maximum tolerances of the part so that ifthe sides of passageway 26 are to grip a part 16 of minimum width, thena lot of resilient wall material must be displaced for a part 16 ofmaximum width. Obviously, the amount of wall material to be displaced issmaller with a toothed wall. Note also in these rectangularconstructions of FIGS. 15, 16, and 17 that the cross-sectional lengthsof passageways 26 can be greater than the cross-sectional lengths ofparts 16, so that there is room to turn a part 16 in a passageway 26 ifneeded. My prior application Ser. No. 195,347 describes turning of parts16 in passageways 26. The widths of passageways may be somewhat narrowerthan depicted in FIGS. 15-17 but the widths have been exaggerated forclarity of illustration.

Having thus described my invention, I do not want to be understood aslimiting myself to the exact details described. Instead, I wish to coverthose modifications of my invention that will occur to those skilled inthe art upon learning of my invention and which properly fall within thescope of my invention.

I claim:
 1. A plate to support a multiplicity of miniature electronicparts such as capacitors, resistors or the like, used in coating ends ofthe parts, comprising:(a) a substantially rigid plate-like body having amultiplicity of juxtaposed parallel bores therethrough, and (b)resilient material coating said bores and defining passageways havingresilient walls of substantially uniform cross section from end to endof said passageways and substantially from face to face of said body,each passageway having at least one cross-sectional dimension shorterthan the corresponding cross-sectional dimension of each part and saidresilient walls of said passageways being capable of continuouslyresiliently gripping such parts in all positions in said passagewayswhether protruding from either end of said passageways or whethercompletely contained within said passageways.
 2. The subject matter ofclaim 1 wherein said passageways are adapted to accept parts of squarecross-sections and have circular cross-sections the diameter of which isless than the distance between opposite corners of a square partcross-section.
 3. The subject matter of claim 1 wherein said passagewayshave cross-sections in the forms of elongated rectangles, thecross-sectional dimension of each passageway being less in width thanthe corresponding dimension of a part for frictionally gripping suchpart, and being greater in length than the corresponding dimension of apart to allow turning of such part in the passageway.
 4. The subjectmatter of claim 1 wherein said passageways have cross-sections in theforms of elongated rectangles, the longer sides thereof being spacedapart a distance greater than the width of a part and having at leastone part of opposed bosses extending inwardly therefrom, the distancebetween the confronting ends of the bosses being less than the width ofa part for resiliently frictionally gripping a part between them aspaced distance inwardly of said longer sides.
 5. A plate to support amultiplicity of miniature electronic parts such as capacitors, resistorsor the like, used in coating ends of the parts, comprising:(a) aplate-like body having a multiplicity of juxtaposed parallel passagewaysextending from face to face of said body, said plate-like body having aplanar recess in each face extending throughout all but marginal areasthereof and said plate-like body also having a multiplicity ofjuxtaposed bores extending therethrough in the areas of said recesses,resilient material filling said recesses and said bores except forforming said passageways which are centered in said bores, said bodybeing formed of rigid material except for said resilient materialfilling said bores and recesses, (b) said passageways having resilientwalls of substantially uniform cross section from end to end of saidpassageways and substantially from face to face of said body, eachpassageway to have at least one cross-sectional dimension shorter thanthe corresponding cross-sectional dimension of each part and saidresilient walls of said passageways being adapted to continuouslyresiliently grip such parts in all positions in said passageways whetherprotruding from either end of said passageways or whether completelycontained within said passageways.